Solve for $x$ and $y$ using substitution. ${5x-3y = -5}$ ${y = -x-9}$
Answer: Since $y$ has already been solved for, substitute $-x-9$ for $y$ in the first equation. ${5x - 3}{(-x-9)}{= -5}$ Simplify and solve for $x$ $5x+3x + 27 = -5$ $8x+27 = -5$ $8x+27{-27} = -5{-27}$ $8x = -32$ $\dfrac{8x}{{8}} = \dfrac{-32}{{8}}$ ${x = -4}$ Now that you know ${x = -4}$ , plug it back into $\thinspace {y = -x-9}\thinspace$ to find $y$ ${y = -}{(-4)}{ - 9}$ $y = 4 - 9$ $y = -5$ You can also plug ${x = -4}$ into $\thinspace {5x-3y = -5}\thinspace$ and get the same answer for $y$ : ${5}{(-4)}{ - 3y = -5}$ ${y = -5}$